Surgical fastener-applying apparatuses with sequential firing

ABSTRACT

A surgical fastening instrument is provided. The surgical fastening instrument includes a handle portion and an elongate portion extending distally from the handle portion and defining a longitudinal axis along a length thereof. The surgical fastening instrument also includes an end effector assembly that includes an anvil and a cartridge supported adjacent a distal end of the elongate portion. Each of the anvil and the cartridge includes a tissue contacting surface oriented substantially perpendicular to the longitudinal axis. One or more independently movable pushers is configured to support one or more surgical fasteners. A thrust bar is operatively coupled to the elongate portion, wherein the thrust bar is movable over a predetermined stroke to effect sequential ejection of at least two surgical fasteners of the plurality of surgical fasteners from the cartridge.

BACKGROUND

1. Technical Field

The present disclosure relates generally to surgical fastener-applyingapparatuses and, more specifically, to surgical fastener-applyingapparatuses that employ sequential firing.

2. Background of Related Art

Surgical fastener-applying apparatuses used for applying a plurality offasteners (e.g., surgical staples) through compressed living tissue arewell known in the art. These surgical fastener-applying apparatuses arecommonly employed for closing tissue or organs prior to transaction orresection, for occluding organs in thoracic and abdominal procedures,and for fastening tissue in anastomoses.

Typically, such surgical fastener-applying apparatuses include an endeffector assembly, which includes an anvil assembly and a cartridgeassembly for supporting a plurality of surgical fasteners, anapproximation mechanism for approximating the anvil and cartridgeassemblies, and a firing mechanism for ejecting the surgical fastenersfrom the cartridge assembly.

In certain types of surgical instruments, such as traverse anastomosesstapling instruments, the surgical fasteners are typically configured todeploy simultaneously from the cartridge from which they are supported.Since the surgical fasteners are fired and deployed simultaneously, asignificant amount of force is required by a user to effectively operatea handle of the surgical fastener-applying apparatus.

SUMMARY

The present disclosure relates to a surgical stapling instrument. Thesurgical fastening instrument includes a handle portion and an elongateportion extending distally from the handle portion and defining alongitudinal axis along a length thereof. The surgical fasteninginstrument also includes an end effector assembly that includes an anviland a cartridge supported adjacent a distal end of the elongate portion.Each of the anvil and the cartridge includes a tissue contacting surfaceoriented substantially perpendicular to the longitudinal axis. One ormore independently movable pushers are configured to support one or moresurgical fasteners. A thrust bar is operatively coupled to the elongateportion, wherein the thrust bar is movable over a predetermined stroketo effect sequential ejection of the plurality of surgical fastenersfrom the cartridge.

The present disclosure also relates to an end effector assembly adaptedfor use with a surgical stapling instrument. The end effector includesan anvil assembly and a cartridge assembly. A plurality of independentlymovable pushers is configured to support a plurality of surgicalfasteners. Each of the anvil assembly and cartridge assembly includes atissue contacting surface that is oriented substantially perpendicularto a longitudinal axis of an elongate portion of the surgical staplinginstrument. A camming member is disposed in mechanical cooperation withthe cartridge assembly, wherein the camming member is configured toengage a portion of the surgical stapling instrument to effectsequential firing of the surgical staples from the cartridge assembly.

The present disclosure also relates to a method of surgically joiningtissue via sequentially ejecting surgical fasteners using a surgicalfastening instrument.

BRIEF DESCRIPTION OF FIGURES

Various embodiments of the presently disclosed surgical fasteninginstrument are disclosed herein with reference to the drawings, wherein:

FIG. 1 illustrates a surgical fastening applying instrument including anend effector assembly that employs a firing mechanism for sequentiallyfiring a plurality of surgical fasteners in accordance with embodimentsof the present disclosure;

FIGS. 2A-2C are cut-away side views of a firing mechanism that includesa camming configuration in accordance with an embodiment of the presentdisclosure;

FIGS. 3A-3C are cut-away side views of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIG. 3D is cut-away side view of a firing mechanism that includes analternate camming configuration in accordance with the embodimentdepicted in FIGS. 3A-3C;

FIGS. 3E-3G are cut-away side view of a firing mechanism that includes acamming configuration in accordance with another embodiment of thepresent disclosure;

FIGS. 3H-3J are cut-away side view of a firing mechanism that includes acamming configuration in accordance with another embodiment of thepresent disclosure;

FIGS. 4A-4C are cut-away side views of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIGS. 5A-5C are cut-away side views of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIGS. 6A-6C are cut-away side views of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIG. 6A ₋₁ is a cut-away view taken along line segment 6A₋₁-6A₋₁ of FIG.6A;

FIG. 6D is a cut away side view of a firing mechanism according to afurther embodiment of the present disclosure;

FIGS. 7A-7C are cut-away side views of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIGS. 7D-7F are cut-away side views of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIGS. 8A-8C are cut-away side views of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIGS. 8D-8E are cut-away side views of an alternate cammingconfiguration in accordance with the embodiment depicted in FIGS. 8A-8C;

FIGS. 9A-9C are cut-away side views of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIGS. 9D-9F are cut-away side views of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIG. 9G is perspective views of various structures configured forrotating the camming configurations depicted in FIGS. 9A-9F;

FIG. 9H is a perspective view of a further structure for rotating thecamming configuration according to another embodiment of the presentdisclosure, shown in a first position;

FIG. 9I is a perspective view of the structure of FIG. 9H, shown in asecond position;

FIGS. 10A-10I are cut-away side views of a firing mechanism thatincludes a camming configuration in accordance with another embodimentof the present disclosure;

FIGS. 11A-11C are cut-away side view of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure;

FIGS. 11D-11F are cut-away side view of a firing mechanism that includesan alternate embodiment of the camming configuration depicted in FIGS.11A-11C;

FIG. 12A-12C is a cut-away side view of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure; and

FIG. 12D is a cut away side view of the camming configuration of12A-12C, shown in another position:

FIG. 13A-13C is a cut-away side view of a firing mechanism that includesa camming configuration in accordance with another embodiment of thepresent disclosure.

DETAILED DESCRIPTION

Embodiments of the presently disclosed surgical fastener-applyingapparatuses are described in detail with reference to the drawings,wherein like reference numerals designate similar or identical elementsin each of the several views. In the drawings and the description thatfollows, the term “proximal” refers to the end of the surgical fasteningapparatus that is closest to the operator, whereas the term “distal”refers to the end of the surgical fastening apparatus that is farthestfrom the operator. As appreciated by one skilled in the art, thedepicted surgical fastening apparatus fires fasteners, but it may beadapted to fire any other suitable fastener such as clips and two-partfasteners.

The present disclosure provides a firing mechanism that includes one ormore camming configurations that is configured to sequentially fire anddeploy each of a plurality of surgical fasteners supported within acartridge of an end effector assembly of a surgical fastener-applyingapparatus.

FIG. 1 illustrates one type of surgical fastener-applying apparatus 10(apparatus 10) that may be employed with a firing mechanism (e.g., 100)of the present disclosure. Apparatus 10 is of the transverse anastomosistype (commonly referred to in the art as “TA” type surgical fastenerapparatus available from United States Surgical, a division of Covidien,Norwalk, Conn.) which is often used for stapling a patient's mesenteryor omentum. Apparatus 10 includes a handle 12, an elongate portion 14extending from the handle 12 and an end effector 16. The end effector 16includes an anvil 18 and a cartridge 22. Apparatus 10 also includes apivotably mounted approximating clamp 34 for advancing cartridge 22toward anvil 18, for instance.

For a more detailed explanation of the operation of surgicalfastener-applying apparatus 10 and of the approximation of the cartridgewith the anvil, reference is made to commonly assigned U.S. Pat. No.5,964,394 to Robertson, the entire contents of which are incorporatedherein by reference.

Referring now to FIGS. 2A-2C, and initially with reference to FIG. 2A,an embodiment of the firing mechanism 100 for sequentially applying thefasteners of apparatus 10 is shown. The firing mechanism 100 includes atrigger actuator 102 (see FIG. 1, for example) and an elongate pusher orthrust bar 104 (FIGS. 2A-2C) slidably translatable within elongateportion 14 of the apparatus 10. Trigger actuator 102 is disposed inmechanical cooperation with a proximal end of thrust bar 104 to advancethrust bar 104 distally. For a more detailed description of the triggeractuator 102 and operative features and components associated therewith,reference is again made to U.S. Pat. No. 5,964,394 to Robertson.

A distal end of thrust bar 104 includes a head portion 106 configured toengage at least one pusher 110 to effect ejection of fasteners 108disposed within cartridge 22. In the embodiments illustrated in FIGS.2A-2C, head 106 includes a substantially flat distal end 106 a that isconfigured to contact at least a portion of a wedge or cam 112 (cam112).

Cam 112 is disposed between the head 106 and pusher 110. In theembodiments illustrated in FIGS. 2A-2C, cam 112 includes a distal end112 a and a proximal end 112 b. Distal end 112 a includes a generallyflat configuration. Proximal end 112 b includes a proximal concave orcurved portion 112 c having upper and lower slanted or angled portions112 d, 112 e extending distally therefrom to the proximal end 112 a.Angled portions 112 d, 112 e are neither parallel to each other nordistal end 112 a. Cam 112 is pivotably connected to a pivot pin or campin 120 disposed within a cam slot 114 (slot 114).

Slot 114 may include structure and/or material (e.g., a groove and/orlubricant, not explicitly shown) that facilitates movement of cam 212therein. A spring 116 (e.g., a torsion spring) is disposed within slot114 and proximally biases cam pin 120 within slot 114. Slot 114 isdimensioned such that pivot pin 120 is moveable therein from a proximalposition to a distal position.

In use, prior to actuation of trigger actuator 102, thrust bar 106 is inan initial proximal position (e.g., start position, see FIG. 2A, forexample). Actuation of trigger actuator 102 causes thrust bar 104 totranslate distally, which causes head 106 to contact cam 112. The shapeof cam 112 in combination with the cam pin 120 force the cam 112 topivot and rotate counter clockwise (as shown by arrow “A” in FIG. 2B).This rotation of cam 112 causes distal translation of the top mostpusher 110 a such that pusher 110 a contacts its corresponding fastener108 a prior to pusher 110 b contacting its corresponding fastener 108 b(FIG. 2B), which, in turn, causes the corresponding fastener(s) 108 a,108 b to sequentially deploy from the cartridge 22 and toward the anvil18. As can be appreciated, the cam 112 sequentially contacts theremaining pushers 110, each of which sequentially contacts itscorresponding fastener 108. This results in sequential firing of all thefasteners 108.

During deployment of the top most fastener(s) 108 (e.g., 108 a, 108 b),spring 116 acts to apply pressure to the cam pin 120 keeping the cam pin120 in place and, thus, preventing the cam 112 from sliding forward.When the cam 112 has rotated to a point where proximal end 112 b of thecam 112 and the head 106 of the thrust bar 104 are substantiallyparallel (as shown in FIG. 2B), the force on the cam 112 overcomes theforce exerted by the spring 116. As result thereof, the top pusher(s)(e.g., 110 a) that has “bottomed out” (i.e., has completely ejected itscorresponding fastener(s) (e.g., 108 a)) acts as a second pivot point(FIG. 2B), which, in turn, causes cam 112 to pivot and rotate clockwise(i.e., in the general direction of arrow “B”) causing the remainingpushers(s) 110 to be pushed distally, which, in turn, causes thecorresponding fastener(s) 108 to deploy from the cartridge 22 and intoanvil pocket(s) on the anvil (FIG. 2C).

While the firing mechanism 100 has been described including one or moresprings 116, it is within the purview of the present disclosure to havethe geometry of the slots 114, pushers 110, cam 112, and/or head 106 ofthrust bar 104 designed such that the spring 116 is not needed for thefiring mechanism to function as intended.

With reference now to FIGS. 3A-3C, and initially with reference to FIG.3A, an alternate embodiment of a firing mechanism is shown generally as200 and described. A distal end of thrust bar 204 includes a headportion 206 that includes a substantially curved distal end 206 a, whichis configured to contact at least a portion of wedge or cam 212. Cam 212is configured to engage at least one pusher 110 to effect sequentialejection of fasteners 108 disposed within cartridge 22.

Cam 212 is disposed between the head 206 and pushers 110. In theembodiments illustrated in FIGS. 3A-3C, cam 212 includes a substantiallyflat distal end 212 a and includes a proximal end 212 b that isconfigured to receive and/or mechanically engage at least a portion ofcurved distal end 206 a of head 206 such that cam 212 may rotate withrespect thereto. In disclosed embodiments, distal end 212 a of cam 212is disposed at an angle α relative to a Y axis (Y-axis is defined by aproximal portion of the pusher(s) 110, see FIG. 3A for example). It isenvisioned that angle α decreases as head 206 is distally translated.Cam 212 is pivotably connected to a pair of pivot pins or cam pins 220a, 220 b respectively disposed within oversized cam slots 214 a and 214b.

Each of slots 214 a, 214 b may have the same or similar configurationsas each other and may include structure and/or material (e.g., a grooveand/or lubricant, not explicitly shown) that facilitates movement of cam212 therein. In the embodiments illustrated in FIGS. 3A-3C, slot 214 ahas a length that is shorter than a length of slot 214 b. A spring 216(e.g., a torsion spring, a compression spring, etc.) is disposed withinslot 214 b and proximally biases pivot pin 220 b within slot 214 b. Inembodiments, the spring 216 may also be disposed within slot 214 a. Slot214 b is dimensioned such that pivot pin 220 is moveable therein from aproximal position to a distal position and also allows small traversemovement.

In use, prior to actuation of trigger actuator 102, thrust bar 206 is inan initial proximal position (e.g., start position, see FIG. 3A, forexample). Actuation of trigger actuator 102 causes thrust bar 204 totranslate distally, which causes head 206 to translate distally whichcauses cam 212 to translate distally. The shape and initial angle α(relative to proximal portion of the pusher(s) 110) of cam 212 incombination with the pivot pins 220 a, 220 b, and spring 216 causes cam212 to translate within slot 214 a. This translation of cam 212 causesthe top most pusher 110 a forward to contact its corresponding fastener108 a prior to pusher 110 b contacting its corresponding fastener 108 b(FIG. 3B), which, in turn, causes the corresponding fastener(s) 108 a,108 b to sequentially deploy from the cartridge 22 and toward the anvil18. As can be appreciated, the cam 212 sequentially contacts theremaining pushers 110, each of which sequentially contacts itscorresponding fastener 108. This results in sequential firing of all thefasteners 110.

During deployment of the top most fastener(s) 108 (e.g., 108 a, 108 b),spring 216 acts to apply pressure to pivot pin 220 b keeping the pivotpin 220 b in place and, thus, preventing a bottom portion of the cam 112from sliding or translating forward. When the upper pivot pin 220 a ofcam 212 has translated to a point within the slot 214 a (e.g., a distalmost end of slot 214, as shown in FIG. 3B) where it is prevented fromfurther translating, the force on the cam 212 exerted by the thrust bar204 overcomes the force exerted on the pivot pin 220 b by the spring216. As a result thereof, cam 212 pivots about the pivot pin 220 acausing the bottom portion of the cam 212 to pivot and rotate clockwise(i.e., in the direction of arrow “C” (angle α approaches 0°)), and thepivot pin 220 b to translate forward within the slot 214 b causing theremaining pushers(s) 110 to be pushed distally, which, in turn, causesthe corresponding fastener(s) 108 to deploy from the cartridge 22 andinto the anvil pocket(s) on the anvil (FIG. 3C). When the lastfastener(s) 108 have been deployed angle α is ≈0°. In other embodiments(not explicitly shown), angle α is less than 0°.

While the embodiment depicted in FIGS. 3A-3C illustrates head 206 ofthrust bar 204 including a substantially curved configuration, it iswithin the purview of the present disclosure to have head 206operatively coupled to cam 212 by way of a slot and pin configuration(see FIG. 3D for example). In this instance, for example, cam 212 mayinclude a curved or angled slot 222 that is operatively disposed thereonand configured to mechanically engage thrust bar 204 by way of a pivotpin or cam pin 224 associated therewith.

Additionally, while the firing mechanism 200 has been describedincluding one or more springs 216, it is within the purview of thepresent disclosure to have the geometry of the slots 214, pushers 110,cam 212, and/or head 206 of thrust bar 204 designed such that a spring216 is not needed for the firing mechanism to function as intended.

With reference to FIGS. 3E-3G, an alternate camming configuration of theembodiment depicted in FIGS. 3A-3D is shown. In the embodimentsillustrated in FIGS. 3E-3G, a distal end of thrust bar 204 includes ahead portion 248 that includes a generally flat distal end 250, which isconfigured to contact at least a portion of wedge or cam 252. Indisclosed embodiments, flat distal end 250 is configured to function asan articulation limiter. That is, the flat distal end 250 is configuredto contact a portion of the cam 252 which, in turn, prevents the cam 252from articulating, to be described in greater detail below. In theembodiment illustrated in FIGS. 3E-3G, distal end 250 is pivotablycoupled to the cam 252 via a pivot pin 254 or the like.

Cam 252 is configured to engage at least one pusher 110 to effectsequential ejection of fasteners 108 disposed within cartridge 22. Tothis end, cam 252 is disposed between the head 248 and pushers 110. Inthe embodiments illustrated in FIGS. 3E-3G, cam 252 includes asubstantially flat distal end 256 and includes a proximal end 258 thatis configured to receive and/or mechanically engage at least a portionof flat distal end 250 of head 248 such that cam 252 may rotate withrespect thereto. Proximal end 258 includes upper and lower slanted orangled portions 262, 264 culminating at a proximal tip 260 that couplesto the distal end 250 of the head portion 248 (FIG. 3F). Proximal tip260 operably couples to the distal end 256 via pivot pin 254. Duringarticulation of the cam 252 each of the angled portions 262, 264 contacta portion of the flat distal end 250 (see FIG. 3F, for example). Contactbetween either of the angled portions 262, 264 and flat distal end 250prevents articulation of the cam 252 in a clockwise and/or counterclockwise direction, respectively. More particularly, when angledportion 262 contacts the flat distal end 250, cam 252 is prevented fromarticulating in a clockwise direction and when angled portion 264contacts the flat distal end 250, cam 252 is prevented from articulatingin a counter-clockwise direction. In the embodiment illustrated in FIGS.3E-3G, each of slots 214 a, 214 b may be replaced by one or more camstops 270 (an upper cam stop 270 a and lower cam stop 270 b are shown)operatively disposed at predetermined locations on or adjacent cartridge22. Each of the upper and lower cam stops 270 a and 270 b, respectively,is configured to impede and/or prevent distal movement of respectiveupper and lower portions 230 and 240 of cam 211. A spring 216 (e.g., atorsion spring, a compression spring, etc.) is disposed within a slot214 d and proximally biases a lower portion 240 of cam 212.

In use, when an upper portion 274 of cam 262 contacts an upper cam stop270 a (FIG. 3F) upper portion 274 is prevented from further translating,the force on the cam 252 exerted by the thrust bar 204 overcomes theforce exerted on lower portion 276 of cam 252 by spring 216. As a resultthereof, cam 252 pivots about a portion of upper cam stop 270 a causingthe bottom portion 274 of the cam 212 to pivot and rotate clockwise(i.e., in the direction of arrow “C₁”), and the bottom portion of thecam 252 is caused to translate forward causing the remaining pushers(s)110 to be pushed distally, which, in turn, causes the correspondingfastener(s) 108 to deploy from the cartridge 22 and into the anvilpocket(s) on the anvil (FIG. 3G). As described previously herein withrespect to FIG. 3C, when the last fastener(s) 108 have been deployedangle α is ≈0°. In other embodiments (not explicitly shown), angle α isless than 0°.

While the embodiment depicted in FIGS. 3E-3G illustrates spring 216operatively associated with lower cam stop 270 _(b), it is within thepurview of the present disclosure to have a spring 216 operativelycoupled to both a portion of a cam 280 and the thrust bar 204 (see FIG.3H, for example). In the embodiment illustrated in FIGS. 3H-3J, thrustbar 204 is operatively connected to an upper portion of a cam 280 andspring 216 may be operably disposed below the pivot pin 254; thisconfiguration, causes the top most pusher 110 a forward to contact itscorresponding fastener 108 a prior to pusher 110 b contacting itscorresponding fastener 108 b (FIG. 3I). Conversely, thrust bar 204 maybe operatively connected to a lower portion (not explicitly shown) ofthe cam 280 and spring 216 may be disposed above the pivot pin 254; thisconfiguration, causes the top most pusher 110 a forward to contact itscorresponding fastener 108 a prior to pusher 110 b contacting itscorresponding fastener 108 b.

Cam 280 is configured to engage at least one pusher 110 to effectsequential ejection of fasteners 108 disposed within cartridge 22. Tothis end, cam 280 is disposed between a head 248 and pushers 110. In theembodiments illustrated in FIGS. 3H-3J, cam 280 includes a substantiallyflat distal end 282 and includes a proximal end 284 that is configuredto receive and/or mechanically engage at least a portion of flat distalend 250 of head 248 such that cam 280 may rotate with respect thereto.Proximal end 284 includes an upper portion 286 having a substantiallyflat configuration and lower portion 288 having a slanted or angledconfiguration. A proximal tip 290 couples to the distal end 250 of thehead portion 248. Proximal tip 290 operably couples to the distal end256 via pivot pin 254. During articulation of the cam 280 each of upperand lower portions 286 and 288, respectively, contact a portion of theflat distal end 250 (see FIG. 3I, for example). Contact between eitherof the upper and lower portions 286 and 288, respectively, and flatdistal end 250 prevents articulation of the cam 280 in a clockwiseand/or counter clockwise direction. More particularly, when upperportion 286 contacts the flat distal end 250, cam 280 is prevented fromarticulating in a clockwise direction and when lower portion 288contacts the flat distal end 250, cam 280 is prevented from articulatingin a counter-clockwise direction. In the embodiment illustrated in FIGS.3H-3I, one or more cam stops 270 (an upper cam stop 270 a and lower camstop 270 b are shown) is operatively disposed at predetermined locationson or adjacent cartridge 22. Each of the upper and lower cam stops 270 aand 270 b, respectively, is configured to impede and/or prevent distalmovement of respective upper and lower portions 292 and 294 of cam 280.

In use, when upper portion 292 of cam 252 contacts an upper cam stop 270a (FIG. 3I) upper portion 292 is prevented from further translating, theforce on the cam 280 exerted by the thrust bar 204 overcomes the forceexerted on the lower portion 288 of cam 280 by a spring 216. As a resultthereof, cam 280 pivots about a portion of upper cam stop 270 a causingthe bottom portion of the cam 280 to pivot and rotate clockwise (i.e.,in the direction of arrow “C₂”, as shown in FIG. 3I), and the bottomportion of the cam 294 is caused to translate forward causing theremaining pushers(s) 110 to be pushed distally, which, in turn, causesthe corresponding fastener(s) 108 to deploy from the cartridge 22 andinto the anvil pocket(s) on the anvil (FIG. 3J). As described previouslyherein with respect to FIGS. 3C and 3G, when the last fastener(s) 108have been deployed angle α is ≈0°. In other embodiments (not explicitlyshown), angle α is less than 0°.

With reference now to FIGS. 4A-4C, and initially with reference to FIG.4A, an alternate embodiment of a firing mechanism is shown generally as300 and described.

A distal end of thrust bar 304 includes a head portion 306 that isconfigured to cause at least one pusher 110 to effect ejection offasteners 108 disposed within cartridge 22. In the embodimentsillustrated in FIGS. 4A-4C, thrust bar 304 includes a distal end 306that operably couples to at least a portion of a wedge or cam 312 (cam312). Distal end 306 includes a vertical slot 314 a configured toreceive one or more pivot pins or cam pins 320 a operably associatedwith the cam 312. Alternatively, the distal end may couple to cam 312 ina manner as described hereinabove with respect to FIGS. 3A-3C.

Cam 312 is disposed between the thrust bar 304 and pushers 110. In theembodiments illustrated in FIGS. 4A-4C, cam 312 includes a distal end312 a having an upper portion 312 a ₁, and a lower portion 312 a ₂. Forillustrative purposes, upper portion 312 a ₁ and a lower portion 312 a ₂are shown separated by imaginary center-line “CL.” Cam 312 also includesa proximal end 312 b includes upper and lower slanted or angled portions312 c, 312 d. Cam 312 includes cam pin 320 a that is in mechanicalcommunication with the slot 314 a of the end 306 a such that cam 312 mayrotate with respect thereto. Distal end 312 a of cam 312 is disposed atan angle α′ relative to a Y′ axis (Y′-axis is defined by a proximalportion of the pusher(s) 110, see FIG. 4A for example). It is envisionedthat angle α′ decreases as head 306 is distally translated. Cam 312 ispivotably connected to one or more pivot pins or cam pins 320 b, 320 cdisposed respectively within one or more cam slots 314 b and 314 c.

In the embodiment illustrated in FIGS. 4A-4C, slots 314 b and 314 c aredisposed at predetermined locations within end effector 16. Each ofslots 314 b and 314 c include proximal and distal ends, with theproximal and distal ends of slot 314 c being longitudinally offset fromeach other, the operation of which to be described in more detail below.Slot 314 c is slanted or angled and is located on cam 312 adjacent tothe lower portion 312 a ₂. Each of slots 314 b and 314 c is dimensionedsuch that pivot pins 320 b, 320 c and/or cam 312 or portion thereof ismoveable therein from a proximal position to a distal position. Althoughnot explicitly shown, it is envisioned that one or more suitable typesof springs may be disposed within any of the slots 314 a, 314 b and 314c.

In use, prior to actuation of trigger actuator 102, thrust bar 304 is inan initial proximal position (e.g., start position, see FIG. 4A, forexample). In the start position, cam pin 320 a is in an initial, bottomposition located within the slot 314 a. Actuation of trigger actuator102 causes thrust bar 304 to translate distally, which causes cam 312 totranslate distally within slot 314 b. The shape and initial angle α′(relative to proximal portion of the pusher(s) 110) of cam 312 incombination with the cam pins 320 b and 320 c and slot configuration,causes the top portion 312 a ₁ of cam 312 to translate within slot 314 band the bottom portion 312 a ₂ to slide within the cam slot 314 c. Thistranslation of top portion 312 a ₁ of cam 312 causes the top most pusher110 a forward to contact its corresponding fastener 108 a prior topusher 110 b contacting its corresponding pusher 110 b (FIG. 4B), which,in turn, causes the corresponding fastener(s) 108 a, 108 b tosequentially deploy from the cartridge 22 and toward the anvil 18. Ascan be appreciated, the cam 312 sequentially contacts the remainingpushers 110, each of which sequentially contacts its correspondingfastener 108. This results in sequential firing of all the fasteners110. During translation of the top portion 312 a ₁ and prior to the topfastener fully forming or “bottoming out” the angle α′ remainsrelatively constant.

When the upper cam pin 320 b of cam 312 has translated to a point withinthe slot 314 b (e.g., a distal most end of slot 314 b, as shown in FIG.4B) where it is prevented from further translating, the force on the cam312 exerted by the thrust bar 304 overcomes the force exerted on the campin 320 c by the lower slot geometry (e.g., slot 314 c). As a resultthereof, cam 312 pivots about the cam pin 320 a causing the bottomportion 312 a ₂ of the cam 312 to pivot and rotate clockwise (i.e., inthe direction of arrow “D” (angle α′ approaches 0°)), and the pivot pin320 b to translate forward within the slot 314 c causing the remainingpushers(s) 110 to be pushed distally, which, in turn, causes thecorresponding fastener(s) 108 to deploy from the cartridge 22 and intothe anvil pocket(s) on the anvil (FIG. 4C). It is envisioned that whenthe last fastener(s) 108 have been deployed, angle α′ is ≈0°.

With reference now to FIGS. 5A-5C, and initially with reference to FIG.5A, an alternate embodiment of a firing mechanism is shown generally as400 and described.

A distal end of thrust bar 404 includes a head portion 406 configured toengage at least one pusher 110 to effect ejection of fastener(s) 108disposed within cartridge 22. In the embodiments illustrated in FIGS.5A-5C, head 406 includes a distal end 406 a that is configured tooperatively couple to one or more links 412 (two links 412 a, 412 b areshown). With this purpose in mind, distal end 406 a includes one or morepivot pins or cam pins 408 (two cam pins 408 are shown) that operativelycouple to the links 412.

Each of links 412 a, 412 b is disposed between the head 406 and pushers110. Each of the links 412 a, 412 b includes a respective distal pushercontacting surface 412 a ₁, 412 b ₁, and a proximal surface 412 a ₂, 412b ₂ that mechanically engages distal end 406 a of head portion 406. Inembodiments, for example, one or more pivot pins 408, rivets, etc.mechanically couples each of proximal surfaces 412 a ₂, 412 b ₂ todistal end 406 a. Each link 412 a, 412 b is pivotably connected to a campin or pivot pin 418 disposed within a respective cam slot 416 (slots416).

Each of slots 416 may have the same or similar configurations and/orgeometries as each other and may include structure and or material(e.g., a groove and/or lubricant, not explicitly shown) that facilitatesmovement of links 412 a, 412 b therein. Slots 416 are located atpredetermined positions within the end effector 16. Slots 416 eachinclude proximal and distal ends 416 a, 416 b. In embodiments, slots 416may include a portion that is bent, arcuate or curved near or at adistal end thereof. One or more springs (e.g., spring 116) may bedisposed within each of the slots 416. Each of slots 416 is dimensionedsuch that pivot pins 418 and/or links 412 a, 412 b, or portions thereof,are moveable therein between a proximal position to a distal position.

In use, prior to actuation of trigger actuator 102, thrust bar 406 is inan initial proximal position (e.g., start position, see FIG. 5A, forexample). Proximal translation of trigger actuator 102 causes thrust bar404 to translate distally, which causes the cam pins 418 and the links412 a, 412 b to translate within the slots 416. This translation of thecam pins 418 and the links 412 a, 412 b causes the outer most pusher(s)(e.g., 110 a, 110 n) distally to contact their corresponding outer mostfastener(s) (e.g., 108 a, 108 n) prior to pusher(s) 110 b, 110 mcontacting their corresponding pushers 110 b, 108 m (FIG. 4B), which, inturn, causes the corresponding fastener(s) 108 a, 108 n to substantiallysimultaneously deploy from the cartridge 22 and toward the anvil 18. Ascan be appreciated, the links 412 sequentially contact the remainingpushers 110, each of which sequentially contacts its correspondingfastener 108.

When the pivot pins 418 of links 412 a, 412 b have translated to a pointwithin the slots 416 where they are prevented from further translating(e.g., a distal most end of slots 416), the force exerted on the links412 a, 412 b by thrust bar 404 causes the links 412 a, 412 b to pivotabout the pivot pins 418. As a result thereof, the links 412 a, 412 brotate clockwise (i.e., in the direction of arrow “E”) and counterclockwise (i.e., in the direction of arrow “F”), respectively, causingthe remaining pushers(s) 110 to be pushed distally (from the outermostpusher(s) 110 to the middle pusher(s) 110), which, in turn, causes thecorresponding fastener(s) 108 to deploy from the cartridge 22 and intothe anvil pocket(s) on the anvil 18 (FIG. 5C).

With reference now to FIGS. 6A-6C, and initially with reference to FIG.6A, an alternate embodiment of a firing mechanism is shown generally as500 and described.

A distal end of thrust bar 504 includes a head portion 506 in mechanicalcommunication with at least two sets of pushers 110 a and 110 b toeffect ejection of two sets of corresponding fasteners 108 a and 108 bdisposed within cartridge 22 (as best seen in FIG. 6B). Head portion 506is positioned within an upper half of the cartridge 22. In theembodiments illustrated in FIGS. 6A-6C, a distal end 506 a of headportion 506 is configured to function as a rack in a rack and pinionconfiguration. To this end, distal end 506 a includes a plurality ofteeth 508 a that are configured to engage or mesh with a plurality ofteeth 508 b operatively associated with a driving disc 510 (configuredto function as a pinion in a rack and pinion configuration) operativelydisposed within the cartridge 22. In the embodiment illustrated in FIGS.6A-6C, the plurality of teeth 508 a is positioned on a bottom portion ofthe head 506. Alternatively, the plurality of teeth 508 a may bepositioned on a top portion of the head 506; this configuration of theplurality of teeth 508 a on the top portion of the head 506 is suitablewhen the head portion 506 is positioned within a lower half of thecartridge 22.

Driving disc 510 may include any suitable geometric configuration. Inthe embodiment illustrated in FIGS. 6A-6C, driving disc 510 includes agenerally circumferential configuration. Driving disc 510 includes twogenerally circumferential opposing side surfaces 516, 518. Driving disc510 is configured to rotate against a frame that supports the cartridge22. To this end, driving disc 510 includes an offset, generallycircumferential gear wheel 512 including a plurality of teeth 508 b.Gear wheel 512 is operably disposed along one of the side surfaces 516,518 of driving disc 510 (gear wheel 512 is shown disposed along sidesurface 516). The gear wheel 512 is configured such that as thrust bar504 is translated distally, the plurality of teeth 508 a at the distalend 506 a engage or mesh with the plurality of teeth 508 b on the gearwheel 512. A first drive pin 520 is operatively disposed on side surface516 and a second drive pin 522 is operatively disposed on side surface518. The drive pins 520, 522 are configured to transfer the rotationalmotion of the drive disc 510 to a yoke mechanism 524. First drive pin520 is located adjacent a peripheral edge of the driving disc 510 (FIG.6A). Likewise, second drive pin 522 is located adjacent a peripheraledge of the driving disc 510 (FIG. 6A). The first drive pin 520 ismovable from a first position, wherein the first drive pin 520 ispositioned distally relative to the second drive pin 522 (FIG. 6A), to asubsequent or final position, wherein the first drive pin 520 ispositioned proximally relative to the second drive pin 522 (FIG. 6C).

Yoke mechanism 524 is in mechanical communication with the driving disc510 and the pushers 110 a and 110 b. More particularly, the yokemechanism includes a first cam member or slide 526 and a second cammember or slide 528 that are movable with respect to each other andconfigured to contact a respective set of pushers 110 a and 110 b (asbest seen in FIG. 6B). To this end, each of the first and second slides526 and 528, respectively, includes a distal, substantially flat pushercontacting surface 526 a and 528 a. The first slide 526 and second slide528 are movably disposed laterally and longitudinally offset from eachother. More particularly, the first slide 526 is movable from an initialposition, wherein the first slide is positioned distally relative to thesecond slide 528 (as best seen in FIG. 6A), to a subsequent or finalposition, wherein the first slide 526 is positioned proximally relativeto the second slide 528 (as best seen in FIG. 6C). The first slide 526operably couples to the first drive pin 520 and the second slide 528operatively couples to the second drive pin 522 (FIG. 6A-1). The firstslide 526 is in operative communication with the first set of pushers110 a and the second slide 528 is in operative communication with thesecond set of pushers 110 b, such that rotation of the driving disc 510rotates the drive pins 520 and 522, which, in turn, translates arespective slide 526 and 528 distally toward a respective pusher 110 aand 110 b. More particularly, the first slide 526 is configured tocontact pusher 110 a, which, in turn, causes a corresponding pluralityof fasteners 108 a to deploy from the cartridge 22 and into the anvilpocket(s) on the anvil. Similarly, second slide 528 is configured tocontact pusher 110 b, which, in turn, causes a corresponding pluralityof fasteners 108 b to deploy from the cartridge 22 and into the anvilpocket(s) on the anvil.

In use, prior to actuation of trigger actuator 102, thrust bar 504 is inan initial proximal position (e.g., start position, see FIG. 6A).Actuation of trigger actuator 102 causes thrust bar 504 to translatedistally, which causes the plurality of teeth 508 a to contact theplurality of teeth 508 b causing the driving disc 510 to rotate in acounter-clockwise direction (see FIG. 6B, for example). As driving disc510 rotates, first and second drive pins 520 and 522, respectively,cause a respective slide 526 and 528 to translate distally toward therespective set of pushers 110 a and 110 b. The spacing configuration ofthe slides 526 and 528 in combination with the positioning of the firstand second drive pins 520 and 522, respectively, on the driving disc 510facilitate in forming the set of surgical fasteners 108 a first, andsubsequently deploying and forming the set of surgical fasteners 108 bnext. More particularly, because the first slide 526 is positioneddistal the slide 528, first slide 526 contacts the set of pushers 110 aprior to the second slide 528 contacting the set of pushers 110 b. Thus,the set of fasteners 108 a deploy from the cartridge 22 and into theanvil pocket(s) on the anvil first. Continued rotation of the drivingdisc 510 causes the first and second driving pins 520 and 522,respectively, to continue to rotate, which, in turn, causes the firstslide 526 to translate proximally and away from the pusher 110 a (thisminimizes a bending load on the anvil), and the second slide 528 tocontinue to translate distally toward the set of pushers 110 b such thatthe plurality of fasteners 108 b deploy from the cartridge 22 and intothe anvil pocket(s) on the anvil (FIG. 6C).

In use, prior to actuation of trigger actuator 102, thrust bar 504 is inan initial proximal position (e.g., start position, see FIG. 6A, forexample). Actuation of trigger actuator 102 causes thrust bar 504 totranslate distally causing the driving disc 510 to rotate in acounter-clockwise direction (see FIG. 6B, for example). As driving disc510 rotates, first and second drive pins 520 and 522, respectively,cause a respective slide 526 and 528 to translate distally toward therespective set of pushers 110 a and 110 b. The spacing configuration ofthe slides 526 and 528 in combination with the positioning of the firstand second drive pins 520 and 522, respectively, on the driving disc 510facilitate in foaming the set of surgical fasteners 108 a first, andsubsequently deploying and forming the set of surgical fasteners 108 bnext. More particularly, because the first slide 526 is positioneddistal the slide 528, first slide 526 contacts the set of pushers 110 aprior to the second slide 528 contacting the set of pushers 110 b. Thus,the set of fasteners 108 a deploy from the cartridge 22 and into theanvil pocket(s) on the anvil first. Continued rotation of the drivingdisc 510 causes the first and second driving pins 520 and 522,respectively, to continue to rotate, which, in turn, causes the firstslide 526 to translate proximally and away from the pusher 110 a (thisminimizes a bending load on the anvil), and the second slide 528 tocontinue to translate distally toward the set of pushers 110 b such thatthe plurality of fasteners 108 b deploy from the cartridge 22 and intothe anvil pocket(s) on the anvil (FIG. 6C).

With reference now to FIGS. 7A-7C, and initially with reference to FIG.7A, an alternate embodiment of a firing mechanism is shown generally as600 and described.

A distal end of thrust bar 604 includes a head portion 606 configured toengage at least one pusher 110 to effect ejection of fastener(s) 108disposed within cartridge 22. In the embodiments illustrated in FIGS.7A-7C, head 606 includes a distal end 606 a that is configured tooperatively couple to links 612 (three links 612 a, 612 b, 612 c areshown). With this purpose in mind, distal end 606 a includes one or morepivot pins or cam pins 608 that operatively couple to the links 612 a,612 b.

Each link 612 a, 612 b, and 612 c is disposed between head 606 andpushers 110. Link 612 a includes a proximal end operatively coupled(e.g., by way of pivot pin 608) to a top portion of the distal end 606 aof head 606 and a distal end that operatively couples to a bottomportion of link 612 c by way of a pivot pin or cam pin 614. Link 612 bincludes a proximal end operatively coupled to a bottom portion of thedistal end 606 a of head 606 (e.g., by way of pivot pin 608) and adistal end that operatively couples to a top portion of link 612 c byway of a pivot pin 608. Link 612 c includes a distal pusher contactingsurface 612 c ₁ that is configured to contact and force one or morepushers 110 distally. Each link 612 a, 612 c operatively couples and/ormechanically engages a slot 616.

Pivot pin 614 is configured to translate within a slot 616 operativelydisposed adjacent a bottom portion of the end effector. Slot 616 mayhave the same or similar configurations and/or geometries ashereinbefore described slots. Additionally, slot 616 may includestructure and/or materials (e.g., a groove and/or lubricant, notexplicitly shown) that facilitates movement of pivot pin 614 therein.Slot 616 is located at a predetermined position within the end effector16. Slot 616 includes proximal and distal ends 616 a, 616 b,respectively. As with the previously described slots (e.g., slots 414),in embodiments, slot 616 may include a portion that is bent, arcuate orcurved adjacent distal end 616 b thereof; this bend or arcuate portionprovides a path for the link 612 c, such that at least a portion of thelink 612 c (e.g., a bottom portion adjacent pivot pin 614) “overshoots”and causes the surgical fasteners away from a “throat” of the anvil tomove. A spring (e.g., spring 116) may be disposed within slot 616 forproximally biasing pivot pin 614. Slot 616 is dimensioned such thatpivot pin 614 and/or links 612 a, 612 c, or portion thereof, is moveabletherein from a proximal position to a distal position.

In use, prior to actuation of trigger actuator 102, thrust bar 606 is inan initial proximal position (e.g., start position, see FIG. 7A, forexample). Actuation of trigger actuator 102 causes thrust bar 604 totranslate distally, which causes the pivot pin 614 and portions of thelinks 612 a, 612 b, and 612 c to translate distally (links 612 a and 612c within the slot 616). This translation causes the bottom most pushers110 n distally (FIG. 7B) to contact its corresponding fasteners 108 nprior to pusher 110 m contacting its corresponding fastener 108 m (FIG.7B), which, in turn, causes the corresponding fastener(s) 108 n, 108 mto sequentially deploy from the cartridge 22 and toward anvil 18.

When the pivot pin 614 and links 612 a, 612 c have translated to a pointwithin the slot 616 where they are prevented from further distallytranslating (e.g., a distal most end of slot 616), the force exerted onthe link 612 c by thrust bar 604 causes the link 612 c to pivot aboutthe “bottom out point” within the slot 616. As a result, the link 612 cis caused to rotate counter clockwise (i.e., in the direction of arrow“H”, see FIG. 7B) causing the remaining pushers 110 to be pusheddistally, which, in turn, causes the corresponding fasteners 108 todeploy from the cartridge 22 and into anvil pocket(s) on the anvil 18(FIG. 7C). This results in sequential firing of all the fasteners. Asnoted above, the bent or arcuate portion of the slot 616 allows thebottom portion of link 612 c adjacent pivot pin 614 to “overshoot” toform the surgical fasteners 108 away from the “throat” of the anvil.

With reference now to FIGS. 7D-7E, and initially with reference to FIG.7D, an alternate embodiment of a camming configuration for use with thefiring mechanism 600 is described and designated 600 a. So as not toobscure the present disclosure with redundant information, only thosefeatures that are unique to the camming configuration of firingmechanism 600 illustrated in FIGS. 7D-7E will be described herein.

Each link 612 a, 612 b, and 612 c is disposed between head 606 andpushers 110. Link 612 b includes a proximal end operatively coupled to abottom portion of the distal end 606 a of head 606 (e.g., by way ofpivot pin 608) and a distal end that operatively couples to a topportion of link 612 c by way of a pivot pin 608 a. Link 612 a includes agenerally elongated slot 622 that extends along a length of the link 612a. More particularly, link 612 a includes a slot 622 operably disposedadjacent a bottom portion thereof. Slot 622 is configured to couple tothe pivot pin or cam pin 614, such that the pivot pin 614 is movablewithin the slot 622. In the embodiment illustrated in FIGS. 7D-7E, link712 c is disposed at an angle β′ with respect to a Y′ axis. Link 712 cmaintains this angle β′ with respect to the Y′ axis during translationof the link 712 c within the cartridge 22 until the pivot pin 608 abottoms out.

Each of pivot pins 608 a and 614 is configured to translate withinrespective slot 620 and 616, with the pivot pin 614 also configured totranslate within the slot 622. Slot 616 is configured as previouslydescribed herein. Slot 620 is operatively disposed adjacent a topportion of the end effector. Slot 620 may have the same or similarconfigurations and/or geometries as hereinbefore described slots.Additionally, slot 620 may include structure and/or materials (e.g., agroove and/or lubricant, not explicitly shown) that facilitates movementof pivot pin 608 a therein. Slot 620 is located at a predeterminedposition within the end effector 16. Slot 620 includes proximal anddistal ends 620 a, 620 b, respectively. As with the previously describedslots (e.g., slot 616), in embodiments, slot 620 may include a portionthat is bent, arcuate or curved adjacent distal end 620 b thereof; thisbend or arcuate portion provides a path for the link 612 c, such that atleast a portion of the link 612 c (e.g., a top portion adjacent pivotpin 608 a) “overshoots” and causes the surgical fasteners away from a“throat” of the anvil to move.

In use, prior to actuation of trigger actuator 102, thrust bar 604 is inan initial proximal position (e.g., see FIG. 7D, for example). Actuationof trigger actuator 102 causes thrust bar 604 to translate distally,which causes the pivot pin 614 and portions of the links 612 a, 612 b,and 612 c to translate distally (links 612 a and 612 c within the slot616, and links 612 b and 612 c within the slot 620). During translationof the links 612 a, 612 b, and 612 c within the respective slots, link712 c maintains the angle β′ with respect to the Y′ axis duringtranslation of the link 712 c within the cartridge 22 until the pivotpin 608 a “bottoms out.” This translation causes the top most pushers110 a distally (FIG. 7E) to contact its corresponding fasteners 108 aprior to pusher 110 b contacting its corresponding fastener 108 b (FIG.7E), which, in turn, causes the corresponding fastener(s) 108 m, 108 nto sequentially deploy from the cartridge 22 and toward anvil 18.

When the pivot pin 608 a and links 612 b, 612 c have translated to apoint within the slot 620 where they are prevented from further distallytranslating (e.g., a distal most end of slot 620), the force exerted onthe link 612 c by thrust bar 604 causes the link 612 c to pivot aboutthe “bottom out point” within the slot 620. As a result, the link 612 bis caused to rotate clockwise (i.e., in the direction of arrow “H₁”, seeFIG. 7E) causing the remaining pushers 110 to be pushed distally, which,in turn, causes the corresponding fasteners 108 to deploy from thecartridge 22 and into anvil pocket(s) on the anvil 18. This results insequential firing of all the fasteners (FIG. 7F). As noted above, thebent or arcuate portion of the slot 616 allows the bottom portion oflink 612 c adjacent pivot pin 614 to “overshoot” to form the surgicalfasteners 108 away from the “throat” of the anvil.

With reference now to FIGS. 8A-8E, and initially with reference to FIG.8A, an alternate embodiment of a firing mechanism is shown generally as700 and described.

A distal end of thrust bar 704 includes a head portion 706 configured toengage at least one pusher to effect ejection of fastener(s) 108disposed within cartridge 22. In the embodiments illustrated in FIGS.8A-8C, head 706 includes a distal end 706 a that is configured tomechanically engage one or more links 712 (three links 712 a, 712 b, 712c are shown). With this purpose in mind, distal end 706 a may have anysuitable shape and may include structure that operatively couples distalend 706 a to the one or more of links 712 (e.g., link 712 a). Forexample, a distal end 706 a may operatively couple to one or more links712 by way of a cam slot and cam pin configuration. More particularly,distal end 706 a of head portion 706 includes an elongated verticallydisposed cam slot 730 that is configured to operably couple to acorresponding cam pin 714 disposed on link 712 a.

Each of links 712 a, 712 b, and 712 c is disposed between the head 706and pushers 110. Link 712 a includes a bottom end pivotably connected tothe end effector 16 by way of a pivot pin 738 (or the like) and a topend operatively coupled to a top end of link 712 b by way of a pivot pinor cam pin 718 that is operatively associated with a slot 716 adjacentthe distal end 706 of thrust bar 704. Link 712 a includes a proximal endthat includes a cam pin 714 that is operably disposed within the camslot 730 and operably couples the distal end 706 a to the link 712 a.Link 712 b includes a top end that is pivotably coupled to link 712 avia pivot pin 718 and a bottom end that pivotably couples to a bottomend of link 712 c via a pivot pin or cam pin 734 that is operativelyassociated with a slot 736. Link 712 c includes a bottom end thatpivotably connects to the bottom end of link 712 b and a top end thatpivotably connects to the end effector by way of a pivot pin 732 (or thelike). Link 712 c includes a distal pusher contacting surface 712 c ₁that is configured to contact and force forward one or more pushers 110.

Pivot pins 718, 734 are configured to translate within the slots 716 and736, respectively, and are operatively disposed adjacent a top portionand bottom portion, respectively, of the end effector. Slots 716 and 736may have the same or similar configurations and/or geometries ashereinbefore described slots. Additionally, slots 716 and 736 mayinclude structure and/or material (e.g., a groove and or lubricant, notexplicitly shown) that facilitates movement of links 712 a, 712 b, and712 c therein (e.g., a groove, not explicitly shown). Slots 716 and 736are located at a predetermined position within the end effector 16. Slot716 includes respective proximal and distal ends 716 a, 716 b. Likewise,slot 736 includes respective proximal and distal ends 736 a, 736 b. Aswith previously described slots (e.g., slot 720), slots 716, 736 includea portion that is arcuate or curved near or at a distal end thereof.More particularly, the curved distal ends of each of the slots 716, 736extend inwardly and toward one another. The slots 716, 736 includeradiuses of curvature that are equal to each other. A spring (e.g., 116)may be disposed within slots 716, 736 and coupled to pivot pins 718, 734and/or links 712 a, 712 b, or portions thereof. Slots 716, 736 aredimensioned such that the respective pivot pins 718, 734 and/or links712 a, 712 b, or portions thereof, is moveable therein from a proximalposition to a distal position.

In use, prior to actuation of trigger actuator 102, thrust bar 706 is inan initial proximal position (e.g., start position, see FIG. 8A, forexample). Actuation of trigger actuator 102 causes thrust bar 704 totranslate distally. As head 706 translates distally, the configurationof links 712 in combination with the cam pins 718 and 734 force the link712 a to translate distally within the slots 716, 736 and link 712 b topivot counter clockwise (i.e., in the direction of arrow “I”) whichcauses link 712 c to pivot and rotate clockwise (i.e., in the directionof arrow “J”). This rotation of links 712 b, 712 c causes distaltranslation of the top most pusher 110 a to contact its correspondingfastener 108 a prior to pusher 110 b contacting its correspondingfasteners 108 b (FIG. 8B), which, in turn, causes the correspondingfastener(s) 108 a, 108 b to sequentially deploy from the cartridge 22and toward the anvil 18. As can be appreciated, the link 712 csequentially contacts the remaining pushers 110, each of whichsequentially contacts its corresponding fastener 108. This results insequential firing of all the fasteners 110 (FIG. 8C).

In certain embodiments, the distal end 706 a of head 706 may operablycouple to the link 712 a via one or more other suitable configurations.For example, a firing mechanism 700 a may include a distal end 706 a ₋₁having a generally “L” shape, see FIG. 8D, for example (or “T” shape,not explicitly shown). Alternatively, a firing mechanism 700 b mayinclude a distal end 706 a ₋₂ having a generally rounded shape (FIG.8E). In each of the embodiments illustrated in FIGS. 8D and 8E, each ofthe respective distal ends 706 a ₋₁ and 706 a ₋₂ is configured tocontact the link 712 a during distal translation of the thrust bar 704.The operational and functional features of each the firing mechanism 700a and 700 b depicted in FIGS. 8D and 8E, respectively, is identical tothat of the firing mechanism 700 depicted in FIGS. 8A-8C and, as aresult thereof, will not be described in detail any further.

With reference now to FIGS. 9A-9G, and initially with reference to FIG.9A, an embodiment of a firing mechanism is shown generally as 800 anddescribed.

A distal end of thrust bar 804 includes a head portion 806 configured toengage at least one pusher 110 to effect ejection of fasteners 108disposed within cartridge 22. Head portion 806 is in mechanicalcommunication with one or more a wedges or cams 812 (cam 812). In theembodiments illustrated in FIGS. 9A-9F, a distal end 806 a of the headportion 806 functions as a rack in the rack and pinion configuration andincludes a plurality of teeth 828 (see FIG. 9B, for example) configuredto mesh or engage with a corresponding plurality of teeth 826 of a gearwheel 824 associated with the cam 812, to be described in greater detailbelow. In certain embodiments, an internally disposed groove or channel(not shown) may be operatively disposed along a length of the cartridge22. The channel may be configured to receive a portion of the thrust bar804 and/or head portion 806, or portion(s) thereof (e.g., a distal end806 a of the). To this end, the channel may be proportionatelydimensioned to accommodate translation of the thrust bar 804 and/or headportion 806.

Camming member or cam 812 is disposed between the head 806 and pusher(s)110. The geometry of cam 812 is configured such that cam 812, orportions thereof, is introduced to the pusher(s) 110 in a sequential orconsecutive manner. The cam has a helical configuration and a pluralityof teeth. When rotated, the teeth are advanced with respect to thepushers in a sequential or consecutive manner. To this end, cam 812 ispivotably and/or rotatably mounted within the end effector adjacent theplurality of pusher(s) and proximal relative thereto. More particularly,cam 812 extends substantially parallel along a Y″ axis (FIG. 9A). Cam812 extends or spans at least a length of the pusher(s) 110 and/orfastener(s) 108. In embodiments, cam 812 includes a plurality of spacedapart teeth 820 that extend along the length of cam 812 at predeterminedlocations thereof (see FIGS. 9A-9C, for example). Alternatively, a cam812 a may include a continuous structure having a twisted configuration(see FIGS. 9D-9F, for example). In embodiments, a cam 812 may be biasedproximally by way of one or more springs or the like (not shown).

In the embodiments illustrated in FIGS. 9A-9F, cam 812 includes an axle822 that extends longitudinally through the camming member or cam 812.More particularly, a top portion of the axle 822 operatively couples toa frame of the cartridge 22 and a bottom portion of the axle 822 couplesto a gear wheel 824 that operably couples to the frame of the cartridge22. The gear wheel 824 functions as a pinion in a rack and pinionconfiguration and includes a plurality of teeth 826 (FIG. 9B) configuredto mesh or engage the plurality teeth 828 associated with the distal end806 a. Depending on design constraints associated with the end effector16, the axle 822 and cam 812 may rotate together, or the cam 812 mayrotate with respect to the axle 822.

In further embodiments, the camming member or cam 812 can be rotated bya cable attached to axle 822. Furthermore, the cam 812 can be rotated bya rotating shaft that actuates one or more gears enmeshed with the gearwheel 824. The cam 812 can be rotated utilizing other driver members,such as thrust bars, cables, gears, rotating shafts, etc.

Operation of the firing mechanism 800 is described in terms of use withembodiment illustrated in FIGS. 9D-9E. In use, prior to actuation oftrigger actuator 102, thrust bar 804 is in an initial proximal position(see FIG. 9D, for example). Actuation of trigger actuator 102 causesthrust bar 804 to translate distally, which causes the plurality ofteeth 828 of the distal end 806 a to mesh or engage the plurality ofteeth 826 on the gear wheel 824. Rotation of the gear wheel 824 causesthe cam 812 to rotate about the Y″ axis in a clockwise direction towardspusher(s) 110, causing the pusher(s) 110 (e.g., bottom most pusher 110n) distally to contact its corresponding fastener(s) (e.g., bottom mostfastener 108 n) prior to pusher 110 m contacting its correspondingfastener 108 m, which, in turn, causes the corresponding fastener(s) 108n, 108 m to sequentially deploy from the cartridge 22 and toward theanvil. As can be appreciated, the cam 812 sequentially contacts theremaining pushers 110, each of which sequentially contacts itscorresponding fastener 108 (see FIGS. 9E and 9F, for example).Additionally, it is contemplated and within the scope of the presentdisclosure that each tooth 820 of camming member or cam 812 directlycontacts a fastener 110. Additionally, it is envisioned that each tooth820 or each pusher 110 contacts more than one fastener 110 (see FIG. 9B,for example).

As shown in FIG. 9D, the camming member or cam 812 can have a helicalconfiguration with an edge that sequentially contacts pushers as the camis rotated, in contrast to the plurality of teeth shown in FIG. 9A, forexample.

FIG. 9G illustrates alternative methods and/or structures for rotatingthe cam 812.

More particularly, in the embodiment illustrated in FIG. 9G cammingmember or cam 812 includes a generally cylindrical bottom portion 812 cand an axle 830 that extends longitudinally through the cam 812. A topportion of the axle 830 operatively couples to a frame of the cartridge22 and a bottom portion of the axle 830 couples to the frame of thecartridge 22 (as described hereinbefore with respect to FIGS. 9A-9F)). Aseparate gear wheel 832 functions as a pinion in a rack and pinionconfiguration and includes a plurality of teeth 834. The gear wheel 832is operatively disposed adjacent to the cam 812. The gear wheel 832operably couples (via an axle or pin 836) to the frame of the cartridge22. A generally cylindrical member 838 extends from a top surface of thegear wheel 832 and includes a diameter of suitable proportion, such thata pulley 840 may be tautly wrapped therearound. More particularly, apulley 840 provides mechanical communication between the cam 812 and thecylindrical member 838. In the embodiment illustrated in FIG. 9G, adistal end 806 a of the head portion 806 functions as a rack in the rackand pinion configuration and includes a corresponding plurality of teeth828 configured to mesh or engage with the plurality of the teeth 834 ofthe gear wheel 832, as described above with respect to FIGS. 9D-9F. Inthe embodiment illustrated in FIG. 9G, distal movement of the distal end906 a causes the gear wheel 832 to rotate in a clockwise direction,which, in turn, causes the cylindrical member 838 and, thus, the pulley840 to also rotate in the clockwise direction. Clockwise rotation of thepulley 840 causes the cam 812 to rotate, which, in turn, causes thepusher(s) 110 and corresponding fastener(s) 108 to deploy in a manner asdescribed hereinbefore with respect to FIGS. 9D-9F.

With reference now to FIGS. 10A-10C, and initially with reference toFIG. 10A, an alternate embodiment of a firing mechanism is showngenerally as 900 and described.

A distal end 904 a of a thrust bar 904 operatively couples (e.g., rivetor pin not explicitly shown) to a bendable member 906 configured toengage at least one pusher 110 to effect ejection of fasteners 108disposed within cartridge 22. In the embodiments illustrated in FIGS.10A-10C, bendable member 906 includes a distal end 906 b thatoperatively couples to a wedge or cam 912 and a proximal end 906 a thatoperatively couples to or is fowled with the distal end 904 a of thrust904. Bendable member 906 may be configured from any suitable materialknown in the art including but not limited to metals, plastics, etc. Inembodiments, bendable member 906 is formed of a thin sheet of metal ormetal alloy or wire. Bendable member 906 may ride along or within atrack or channel 920 that extends within the end effector (see FIG. 10A,for example). A bendable member 922 (similar to that of bendable member906) includes a distal end 922 a that operatively couples to a topportion of the wedge or cam 912 and a proximal end 922 b thatoperatively couples to or is formed with the distal end 904 a of thrust904. Bendable member 922 includes a degree of slack “S” defined by alength that is approximately equal to the distance that the thrust bar904 translates. In this instance, after the thrust bar 904 hastranslated a distance that is equal to the length of the slack “S”, thebendable member 904 becomes taut between the distal end 922 a coupled tothe top portion of the cam 912 and the proximal end 922 b coupled to thedistal end 904 a of the pusher facilitating resetting the cam 912 to aninitial position.

One or more pulleys 908 (four pulleys are shown) are operativelydisposed at predetermined locations within end effector 16.Alternatively, rivets or non-rotating features may used in place of thepulleys. In embodiments illustrated in FIGS. 10A-10C, a pair of bottompulleys 908 are configured such that as thrust bar 904 is translateddistally the cam 912 is caused to translate in a downward direction, anda pair of top pulleys 908 are configured such that as thrust bar 904 istranslated proximally the cam 912 is caused to translate in an upwarddirection, that is, the cam 912 is reset to an initial position.Alternatively, a pulley 908 is configured such that as thrust bar 904 istranslated distally, the cam 912 is caused to translate in an upwarddirection (see FIGS. 10D-10F, for example).

In the embodiments illustrated in FIGS. 10A-10C, cam 912 includes adistal portion 912 a that is disposed at an angle with respect toproximal portion of pushers 110. A top portion 912 b of cam 912 operablycouples to the distal end 922 a of the bendable member 922 a and abottom portion 912 c operably couples to the distal end 906 b of thebendable member 906 a by any suitable means.

In use, prior to actuation of trigger actuator 102, thrust bar 904 is inan initial proximal position (e.g., start position, see FIG. 10A, forexample). Actuation of trigger actuator 102 causes thrust bar 904 totranslate distally. The pulley configuration forces the cam 912 totranslate downward (as shown by the arrow “K”) within the end effectorand along side the pusher(s) 110. The shape of cam 912 causes the topmost pusher 110 a distally to contact its corresponding fastener 108 aprior to pusher 110 b contacting its corresponding fastener 108 b (FIG.10B), which, in turn, causes the corresponding fastener(s) 108 a, 108 bto sequentially deploy from the cartridge 22 and toward the anvil 18. Ascan be appreciated, the cam 912 sequentially contacts the remainingpushers 110, each of which sequentially contacts its correspondingfastener 108. This results in sequential firing of all the fasteners 108(see FIG. 10C, for example). After all the fasteners have been fired,the thrust bar 904 is in a distal most position and the slack “S”originally associated with the bendable member 922 is not present andthe bendable member 922 is pulled taut (FIG. 10C). Proximal translationof the thrust bar 904 pulls the bendable member 922 which, in turn,facilitates the cam 912 in returning to the initial position (FIG. 10A).As can be appreciated by one of skill in the art, the firing mechanism800 may be configured to function without the need for the top pulleyconfiguration.

With reference now to FIGS. 10D-10F, and initially with reference toFIG. 10D, an alternate embodiment of camming configuration for use witha firing mechanism 900 is described.

Thrust bar 904 is operably disposed adjacent a bottom portion of the endeffector 16. A distal end 904 a of a thrust bar 904 operatively couples(e.g., rivet or pin not explicitly shown) to a bendable member 906configured to engage at least one pusher 110 to effect ejection offasteners 108 disposed within cartridge 22. In the embodimentsillustrated in FIGS. 10D-10F, bendable member 906 includes a distal end906 a that operatively couples to a wedge or cam 912 and a proximal end906 a that operatively couples to or is formed with the distal end 904 aof thrust bar 904. Bendable member 906 may be configured from anysuitable material known in the art including but not limited to metals,plastics, etc. In embodiments, bendable member 906 is formed of a thinsheet of metal or metal alloy or wire. Bendable member 906 may ridealong or within a track or channel 920 that extends within the endeffector.

One or more pulleys 908 (one pulley is shown) is operatively disposed ata predetermined location within end effector 16. Alternatively, rivetsor non-rotating features may used in place of the pulleys. Inembodiments illustrated in FIGS. 10D-10F, a bottom pulley 908 isconfigured such that as thrust bar 904 is translated distally the cam912 is caused to translate in an upward direction.

In the embodiments illustrated in FIGS. 10D-10F, cam 912 includes adistal portion 912 a that is disposed at an angle with respect toproximal portion of pushers 110. A bottom portion 912 a of cam 912operably couples to a distal end 906 a of bendable member 906 by anysuitable means.

In use, prior to actuation of trigger actuator 102, thrust bar 904 is inan initial proximal position (see FIG. 10D, for example). Actuation oftrigger actuator 102 causes thrust bar 904 to translate distally, whichcauses bar 904 to translate distally. The pulley configuration forcesthe cam 912 to translate upward (as shown by the arrow “L”) within theend effector and along side the pusher(s) 110. The shape of cam 912forces the bottom most pusher 110 n distally to contact itscorresponding fastener 108 n prior to pusher 110 m contacting itscorresponding fastener 108 m (FIG. 10E), which, in turn, causes thecorresponding fastener(s) 108 n, 108 m to sequentially deploy from thecartridge 22 and toward the anvil 18. As can be appreciated, the cam 912sequentially contacts the remaining pushers 110, each of whichsequentially contacts its corresponding fastener 108. This results insequential firing of all the fasteners 108 (see FIG. 10F, for example).

In an embodiment illustrated in FIGS. 10G-10I, cam 912 is configured totranslate within tracks 920 that are disposed at predetermined locationsin both the cartridge 22 and anvil 18. In use, as the bendable portionis translated distally, the cam 912 translates upward (or some instancesdownward) causing the pushers 110 and corresponding fasteners 108 todeploy as described above. A knife or cutter (not explicitly shown) maybe incorporated into the cam 912 and configured to cut or sever tissueafter deployment of the pushers 110 and corresponding fasteners 108. Inthe embodiment described in FIGS. 10G-10I, it is envisioned that cam 912helps maintain alignment and spacing between the cartridge 22 and anvil18 during deployment of the fasteners 108 to help improve fastenerformation.

With reference now to FIGS. 11A-11C, and initially with reference toFIG. 11A, an alternate embodiment of a firing mechanism is showngenerally as 1000 and described.

A distal end of thrust bar 1004 includes a head portion 1006 configuredto engage at least one pusher to effect ejection of fasteners 108disposed within cartridge 22. In the embodiments illustrated in FIGS.11A-11C, head 1006 includes a distal end 1006 a that is configured tomechanically engage one or more independently moveable cams 1012 (threecams 1014, 1016, 1018 are shown). With this purpose in mind, distal end1006 a of head 1006 may have any suitable shape and may includestructure that operatively couples distal end 1006 a to one or more ofcams 1012. More particularly, head 1006 includes a generally flat distalend 1006 a configured to contact a bottom cam 1018. Distal end 1006 a isoperably disposed adjacent a bottom portion of the end effector 16.

Each of the cams 1012 is disposed between the head 1006 and pushers 110.In the embodiments illustrated in FIGS. 11A-11C, cams 1012 areconfigured to cause sequential distal translation of the pushers 110.With this purpose in mind, the cams 1012 are positioned one on top ofthe other and in a staggered configuration (see FIG. 11A for example).More particularly, cam 1014 includes substantially flat top surface 1014a that is disposed adjacent a top portion of the end effect 16 and astepped bottom surface 1014 b that is adjacent and corresponds tostepped top surface 1016 a of the cam 1016 (FIGS. 11A-11C). Steppedbottom surface 1014 b includes three steps. The proximal most step beingproportioned to form part of a housing for a resilient member 1020. Cam1014 includes one or more slots 1014 c configured to ensure lineartranslation of the cam 1014 when the cam 1014 is forced distally. Tothis end, slot 1014 c is configured to support or house a cam pin 1014 d(FIG. 11B) moveable therein between a proximal position to a distalposition. A cam 1016 includes stepped top and bottom surfaces 1016 a and1016 b, respectively, that are disposed adjacent stepped bottom surface1014 b of cam 1014 and a stepped top surface 1018 a of the cam 1018,respectively (FIGS. 11A-11C). Stepped top and bottom surfaces 1016 a and1016 b, respectively, include three steps. A middle step of the steppedtop surface 1016 a being proportioned to form part of the housing for aresilient member 1020 and a proximal step of the stepped bottom surface1016 b being proportioned to form part of a housing for a resilientmember 1020. Cam 1016 includes one or more slots 1016 c configured toensure linear translation of the cam 1016 when the cam 1016 is forceddistally. To this end, slot 1016 c is configured to support or house acam pin 1016 d (FIG. 11B) moveable therein between a proximal positionto a distal position. A cam 1018 includes substantially flat bottomsurface 1018 b that is disposed adjacent a bottom portion of the endeffect 16 and a stepped top surface 1018 b that corresponds to steppedbottom surface 1016 b of the cam 1016 (FIGS. 11A-11C). Stepped topsurface 1018 b includes three steps. A middle step being proportioned toform part of a housing for a resilient member 1020. Cam 1018 includesone or more slots 1018 c configured to ensure linear translation of thecam 1018 when the cam 1018 is forced distally. To this end, slot 1018 cis configured to support or house a cam pin 1018 d (FIG. 11B) moveabletherein between a proximal position to a distal position. The steppedconfiguration associated with each of the cams 1012 provides a smooth,linear transition when the cams 1012 are forced distally. Each of thecams 1014, 1016, 1018 includes a respective distal surface 1014 e, 1016e, 1018 e dimensioned to contact one or more pushers 110, and the cam1018 includes a proximal surface 1018 f dimensioned to contact head1006. Distal surface 1014 e of cam 1014 is initially disposed distallyrelative to distal surface 1016 e of cam 1016 and distal surface 1018 e.And, distal surface 1016 e of cam 1016 is initially disposed distallyrelative to distal surface 1018 e of cam 1018. Accordingly, the distalsurface of cam 1014 contacts a corresponding set of pusher(s) first, thedistal surface of cam 1016 contacts a corresponding set of pusher(s)next, and so on.

One or more resilient members or springs 1020 is disposed between thecam 1014 and 1016, and one or more springs 1020 is disposed between thecams 1016 and 1018 (see FIGS. 11A-11C). More particularly, a spring 1020is disposed between the proximal most step of cam 1014 and the middlestep of the stepped top surface of cam 1016, and a spring 1020 isdisposed between the proximal most step of the stepped bottom surface ofthe cam 1014 and the middle step of cam 1018. The springs 1020 areconfigured to bias the cams 1016 and 1018 proximally and, thus helpensure that distal surfaces of the cams 1012 contact a corresponding setof the pusher(s) 110 sequentially.

In use, prior to actuation of trigger actuator 102, thrust bar 1004 isin an initial proximal position (FIG. 11A, for example). Actuation oftrigger actuator 102 causes thrust bar 1004 to translate distally, whichcauses head 1006 to contact the proximal surface of the cam 1018. Theconfiguration of cams 1012 (i.e., the staggered configuration of thedistal surfaces of each of the cams 1012) in combination with thebiasing force of the springs 1020 provides that each of the cams 1012translate distally together. The springs 1020 include appropriate springconstants such that the distal surfaces 1016 e and 1018 e of the cams1016 and 1018, respectively, do not contact a corresponding pusher(s)until the distal surface 1014 e of the cam 1014 contacts its pusher(s)and bottoms out (FIG. 11B). Accordingly, cam 1014 causes the top mostpusher(s) 110 a distally to contact its corresponding fastener(s) 108 aprior to pusher 110 b contacting its corresponding fastener(s) 108 b(FIG. 11B), which, in turn, causes the corresponding fastener(s) 108 a108 b to sequentially deploy from the cartridge 22 and toward the anvil18.

When cam 1014 has translated to a point where it is prevented fromfurther translating, the force exerted on cam 1016 by thrust bar 1004overcomes the force exerted on the cam 1016 by the he spring 1020, whichcauses the cam 1016 to translate distally. This process continues foreach of the remaining cams, e.g., cam 1018 and so forth, causing theremaining pushers(s) 110 be pushed distally, which, in turn, causes thecorresponding fastener(s) 108 to deploy from the cartridge 22 and intoanvil pocket(s) on the anvil (FIG. 11C). As can be appreciated, each ofthe remaining cams 1012 (e.g., 1018 and so forth) independently andsequentially contacts the remaining pushers 110, each of whichsequentially contacts its corresponding fastener(s) 108. This results insequential firing of all the fasteners 110.

With reference now to FIGS. 11D-11F, an alternate embodiment of acamming configuration for use with a firing mechanism 900 a isdescribed.

A distal end of thrust bar 1004 includes a head portion 1006 configuredto engage at least one pusher to effect ejection of fasteners 108disposed within cartridge 22. In the embodiments illustrated in FIG.11D, head 1006 includes a distal end 1006 a that is configured tomechanically engage one or more independently moveable cams 1040 (threecams 1042, 1044, 1046 are shown). With this purpose in mind, distal end1006 a of head 1006 may have any suitable shape and may includestructure that operatively couples distal end 1006 a to one or more ofcams 1040. More particularly, head 1006 includes a generally flat distalend 1006 a configured to contact a middle cam 1044. Distal end 1006 a isoperably disposed adjacent a middle portion of the end effector 16.

Each of the cams 1040 is disposed between the head 1006 and pushers 110.In the embodiments illustrated in FIG. 11D, cams 1040 are configured tocause sequential distal translation of the pushers 110. With thispurpose in mind, the cams 1040 are positioned one on top of the otherand in a generally staggered configuration (see FIG. 11D for example).More particularly, a pair of top and bottom cams 1042 and 1046 includerespective substantially flat top and bottom surfaces 1042 a, 1046 athat are disposed adjacent respective top and bottom portions of the endeffect 16. A bottom surface 1042 b of the cam 1042 includes a protrusionor nib 1042 c operably disposed at a predetermined position along thesurface 1042 b. Likewise, a top surface 1046 b of the cam 1046 includesa protrusion or nib 1046 c operably disposed at a predetermined positionalong the surface 1046 b. Each of the cams 1042 and 1046 includes arespective distal surface 1042 e and 1046 e configured to contact one ormore corresponding pusher(s) 110. A cam 1044 is in mechanicalcommunication with each of the cams 1042 and 1044 and is operablydisposed therebetween. More particularly, cam 1044 includes a generally“dumbbell” like configuration having a proximal surface 1044 dconfigured to contact a distal end 1006 a of the head 1006 and a distalsurface 1044 e configured to contact one or more corresponding pusher(s)110. A top portion of the cam 1044 includes a gap 1044 f that separatesthe proximal surface 1044 d and distal surface 1044 e. Similarly, abottom portion of the cam 1044 includes a gap 1044 g that separates theproximal surface 1044 d and distal surface 1044 e. Each of the gaps 1044f and 1044 g is configured to accommodate a respective nib 1042 c and1046 c and a resilient member 1020.

One or more resilient members or springs 1020 is disposed between thecam 1042 and 1044, and one or more springs 1020 is disposed between thecams 1044 and 1046 (see FIG. 11D). More particularly, a spring 1020 isdisposed between the nib 1042 c of cam 1042 and a proximal surface 1044d of the cam 1044, and a spring 1020 is disposed between the nib 1046 cof cam 1046 and a proximal surface 1044 d of the cam 1044. The springs1020 are configured to bias the cam 1044 proximally and, thus helpensure that distal surfaces of the cams 1012 contact a corresponding setof the pusher(s) 110 sequentially.

In use, prior to actuation of trigger actuator 102, thrust bar 1004 isin an initial proximal position (FIG. 11D, for example). Actuation oftrigger actuator 102 causes thrust bar 1004 to translate distally, whichcauses head 1006 to contact the proximal surface 1044 d of the cam 1044.The structural configuration of cams 1040 (i.e., the nibs 1042 c and1046 c in combination with the biasing force of the springs 1020)provides that each of the cams 1012 translate distally together. Thesprings 1020 include appropriate spring constants such that the distalsurface 1044 e of the cam 1044 contacts a corresponding pusher(s) untileach of the distal surfaces 1042 e and 1046 e of the cams 1042 and 1046,respectively, contacts its pusher(s) and bottoms out. Accordingly, cams1042 and 1046 cause the top and bottom most pusher(s) 110 a and 110 n,respectively, distally to contact its corresponding fastener(s) 108 aand 108 n, respectively, prior to pusher 110 b contacting itscorresponding fastener(s) 108 b, which, in turn, causes thecorresponding fastener(s) 108 a and 108 n, and 108 b to sequentiallydeploy from the cartridge 22 and toward the anvil 18 (FIG. 11E).

When each of the cams 1042 and 1046 have translated to a point where itis prevented from further translating, the force exerted on cam 1044 bythrust bar 1004 overcomes the force exerted on the cam 1044 by thesprings 1020, which causes the cam 1044 to translate distally causingthe remaining pushers(s) 110 be pushed distally, which, in turn, causesthe corresponding fastener(s) 108 to deploy from the cartridge 22 andinto anvil pocket(s) on the anvil. This results in sequential firing ofall the fasteners 110 (FIG. 11F).

With reference now to FIGS. 12A-12C, and initially with reference toFIG. 12A, an alternate embodiment of a firing mechanism is showngenerally as 1100 and described.

A distal end of thrust bar 1104 includes a head portion 1106 configuredto engage at least one pusher 110 to effect ejection of fasteners 108disposed within cartridge 22. In the embodiments illustrated in FIGS.12A-12C, head 1106 includes a generally curved end 1106 a that isconfigured to contact at least a portion of a wedge or cam 1112 (cam112). A cam or pivot pin 1114 is operably disposed at the curved end1106 a.

Cam 1112 is disposed between the head 1106 and pusher 110. In theembodiments illustrated in FIGS. 12A-12C, cam 1112 includes a distal end1112 a and a proximal end 1112 b. Distal end 1112 a includes a generallyflat configuration. The distal end 1112 a is configured to contact oneor more pushers 110. Proximal end 1112 b includes a proximal portion1112 c having an elongated cam slot 1116. Cam 1112 is pivotablyconnected to the distal end 1106 a of head portion 1106 via the cam slot1116 and pivot pin 1114. A top end of the cam 1112 is pivotably coupledto a top portion of the end effector 16. More particularly, a pivot pin1118 operably couples the cam 1112 to a frame of the cartridge 22. Toensure that all of the pushers 110 and corresponding surgical fasteners108 are ejected or deployed, the pivot pin 1118 is operably disposedin-line with a distal most position of the pushers 110 (FIG. 12A).Alternatively, the pivot pin 1118 may be operably coupled to a topportion of the end effector 16.

Slot 1116 may include structure and/or material (e.g., a groove and/orlubricant, not explicitly shown) that facilitates movement of pivot pin1114 therein.

In use, prior to actuation of trigger actuator 102, thrust bar 1104 isin an initial proximal position (FIG. 12A). Actuation of triggeractuator 102 causes thrust bar 1104 to translate distally, the shape ofcam 1112 in combination with the pivot pin 1114 force the cam 1112 topivot and rotate clockwise (as shown by arrow “M” in FIG. 12B). Thisrotation of cam 1112 causes distal translation of the top most pusher110 a such that pusher 110 a contacts its corresponding fastener 108 aprior to pusher 110 b contacting its corresponding fastener 108 b (FIG.12B), which, in turn, causes the corresponding fastener(s) 108 a, 108 bto sequentially deploy from the cartridge 22 and toward the anvil 18. Ascan be appreciated, the cam 1112 sequentially contacts the remainingpushers 110, each of which sequentially contacts its correspondingfastener 108. This results in sequential firing of all the fasteners108.

With reference now to FIGS. 13A-13C, and initially with reference toFIG. 13A, an alternate embodiment of a firing mechanism is showngenerally as 1200 and described.

A distal end of thrust bar 1204 includes a head portion 1206 configuredto engage at least one pusher 110 to effect ejection of fasteners 108disposed within cartridge 22. In the embodiments illustrated in FIGS.13A-13C, head 1206 may include a generally curved end (not shown) thatis configured to contact at least a portion of a wedge or cam 1212 (cam112). A cam or pivot pin 1214 is operably disposed at the distal end1206 a.

Cam 1212 is disposed between the head 1206 and pusher 110. In theembodiments illustrated in FIGS. 13A-13C, cam 1212 includes a distal end1212 a and a proximal end 1212 b. Distal end 1212 a includes a generallyflat configuration. The distal end 1212 a is configured to contact oneor more pushers 110. Proximal end 1212 b includes an elongated cam slot1216. Cam 1212 is pivotably connected to the distal end 1106 a of headportion 1206 via the cam slot 1216 and pivot pin 1214. A top and bottomedge 1220 and 1222, respectively, of the proximal end 1212 b of the cam1212 is grounded or secured to a top portion of the end effector 16 viaa respective cable 1218 or the like.

Slot 1216 may include structure and/or material (e.g., a groove and/orlubricant, not explicitly shown) that facilitates movement of pivot pin1114 therein.

In use, prior to actuation of trigger actuator 102, thrust bar 1204 isin an initial proximal position (FIG. 13A). Actuation of triggeractuator 102 causes thrust bar 1204 to translate distally, the shape ofcam 1212 in combination with the pivot pin 1214 force the cam 1212 topivot and rotate clockwise (as shown by arrow “N” in FIG. 13B). Thisrotation of cam 1212 causes distal translation of the top most pusher110 a such that pusher 110 a contacts its corresponding fastener 108 aprior to pusher 110 b contacting its corresponding fastener 108 b (FIG.13B), which, in turn, causes the corresponding fastener(s) 108 a, 108 bto sequentially deploy from the cartridge 22 and toward the anvil 18. Ascan be appreciated, the cam 1212 sequentially contacts the remainingpushers 110, each of which sequentially contacts its correspondingfastener 108. This results in sequential firing of all the fasteners108.

The present disclosure also relates to methods of using a surgicalinstrument to sequentially fire fasteners therefrom.

Furthermore, the arrangements shown herein can be utilized in surgicalinstruments that includes a knife, or an instrument that does not have aknife.

It will be understood that various modifications may be made to theembodiments of the presently disclosed surgical stapling instruments.For instance, an embodiment of the presently disclosed surgicalfastening apparatus includes an end effector assembly that includes twocartridge assemblies. An embodiment of the presently disclosed surgicalfastening apparatus includes an end effector that is curved.Additionally, it is envisioned that the firing mechanisms of the presentdisclosure can be used with surgical staplers used for performinganastomoses. Therefore, there above description should not be construedas limiting, but merely as exemplifications of embodiments. Thoseskilled in the art will envision other modifications within the scopeand spirit of the present disclosure.

What is claimed is:
 1. A surgical fastening instrument comprising: ahandle portion; an elongate portion extending distally from the handleportion and defining a longitudinal axis along a length thereof; an endeffector assembly including an anvil and a cartridge supported adjacenta distal end of the elongate portion, each of the anvil and thecartridge including a tissue contacting surface oriented substantiallyperpendicular to the longitudinal axis; at least two independentlymovable pushers supporting at least two surgical fasteners; a thrust baroperatively coupled to the elongate portion, the thrust bar beingmovable over a predetermined stroke to effect sequential ejection of theat least two surgical fasteners of the plurality of surgical fastenersfrom the cartridge; the at least two surgical fasteners being inoperative communication with the at least two independently movablepushers; and a camming member positioned between the thrust bar and theat least two independently movable pushers, the camming member having adistal end configured to contact each of the at least two independentlymovable pushers and a proximal end configured to contact at least aportion of the thrust bar, the camming member being pivotably connectedto the end effector by way of at least one cam pin.
 2. The surgicalfastener instrument of claim 1, wherein the cam pin is movable within acam slot located adjacent the end effector assembly.
 3. The surgicalfastener instrument of claim 1, wherein the camming member is proximallybiased by way of a resilient member.
 4. The surgical fastener instrumentof claim 3, wherein the resilient member is a spring in operativecommunication with the camming member.
 5. The surgical fastenerinstrument of claim 1, wherein the thrust bar is movable over apredetermined stroke to effect sequential ejection of each fastener ofthe plurality of surgical fasteners from the cartridge.